Flexible display device

ABSTRACT

A flexible display device including a first body; a second body; a flexible display unit arranged on a front surface of the first body and the second body; and a hinge unit connecting the first body and the second body to each other such that the first body and the second body can be folded and unfolded with respect to each other. Further, the hinge unit includes a plurality of hinge segments such that in a folding state of the flexible display unit, the second body is arranged to cover a rear surface of the first body as an interval between the hinge segments is increased, and in an unfolded state of the flexible display unit, the first body and the second body are arranged in parallel with the interval between the hinge segments being decreased.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. § 119(e), this application claims the benefit ofan earlier filing date and priority to U.S. Provisional Application No.62/799,705 filed on Jan. 31, 2019, and under 35 U.S.C. § 119(a) toKorean Application Nos. 10-2019-0053851 filed in the Republic of Koreaon May 8, 2019 and 10-2019-0039173 filed in the Republic of Korea onApr. 3, 2019, all of which are hereby expressly incorporated byreference into the present application.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present disclosure relates to a flexible display device, andparticularly, to a flexible display device having a flexible displayunit which is transformable by an external force.

2. Discussion of the Related Art

A portable electronic device (hereinafter, a mobile terminal) such as acommunication terminal, a multimedia device, a portable computer, a gamemachine and a capturing device is provided with a display for displayingvideo information. The mobile terminal may have a folding structure tobe folded into a smaller size, for convenience of portability. In suchan electronic device, two bodies are connected to each other by afolding structure (e.g., a hinge unit).

Since the conventional display has no folding structure, it wasimpossible to implement a structure to arrange a display on two bodiesconnected to each other in a foldable manner. Therefore, it wasimpossible to apply a large screen to an electronic device of a foldingstructure.

However, as a flexible display which can be bent is being developedrecently, research to apply such a flexible display to a mobile terminalis actively ongoing. In this instance, since the flexible display isarranged on two bodies through a folding structure, a large screen canbe implemented.

In a flexible display device, a flexible display is transformable into afolding state and an unfolding state by using a hinge unit. However,when the folding state is converted into the unfolding state or viceversa, an unnecessary load may be applied to the flexible display, or afolding in a reverse direction may be performed to cause inconvenienceto a user.

Therefore, there is provided a mechanism of a flexible display device,capable of having a display long in a vertical direction in a foldingstate for utilization as a smart phone, and having a screen ratio ofabout 1:1 in an unfolding state. Here, considered is a method forproviding a smooth movement of a flexible display unit forimplementation of various states.

SUMMARY OF THE INVENTION

Therefore, an aspect of the detailed description is to provide aflexible display device which can perform folding and unfolding, andwhich can provide a display unit of various sizes to a user, forutilization as a mobile phone, a note and a tablet.

Another aspect of the detailed description is to provide a flexibledisplay device which can perform a smooth movement by folding andunfolding of a flexible display unit, which can smoothly support theflexible display unit in spite of a state change of the flexible displayunit, and which can prevent an unnecessary load from being applied tothe flexible display unit.

To achieve these and other advantages and in accordance with the purposeof this specification, as embodied and broadly described herein, aflexible display device has a structure that one body has one side towhich another body is rotatably connected, and a flexible display unitis foldable.

More specifically, a flexible display device includes: a first bodyhaving a plurality of parts connected to each other so as to berelatively moveable; a second body connected to the first body so as tobe relatively rotatable; a flexible display unit formed to be folded andunfolded, and arranged on a front surface of the first body and thesecond body; and a hinge unit installed at one side of the first body,configured to connect the first body and the second body to each otherfor relative rotation, and formed of a plurality of hinge segments,wherein in a folding state of the flexible display unit, the second bodymay be arranged to cover a rear surface of the first body as an intervalbetween the hinge segments is changed.

Advantageous Effects

Effects of the present disclosure obtained by the aforementionedsolution means are as follows. Firstly, the flexible display unit havingtwo screen sizes of a folding state and an unfolding state can beimplemented through a foldable structure. Secondly, through aninterworking structure of the bodies, a connection operation of afolding state and an unfolding state can be implemented in a compactspace.

Thirdly, through a configuration of the rear plate, the flexible displayunit can be smoothly supported. Also, since a length compensation can beperformed when the flexible display unit is bent, damage of the flexibledisplay unit can be prevented at the time of a folding operation and anunfolding operation.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawings,which are given by illustration only, and thus are not limitative of thepresent invention, and wherein:

FIG. 1 is a block diagram illustrating a mobile terminal according tothe present disclosure.

FIG. 2A is a perspective view of a flexible display device, which showsan outer folding state.

FIG. 2B is a perspective view of the flexible display device, whichshows an unfolding state.

FIGS. 3A and 3B are conceptual views showing implementable states of theflexible display device.

FIG. 4 is a planar view showing an inner form of the flexible displaydevice.

FIG. 5 is a disassembled perspective view of the flexible displaydevice.

FIG. 6 is a perspective view showing a first state of the flexibledisplay device.

FIGS. 7A and 7B are perspective views showing a front surface and a rearsurface of hinge segments of a hinge unit.

FIGS. 8A-8C are conceptual views showing the hinge unit.

FIG. 9 is a perspective view of a rear plate.

FIG. 10A is a partially enlarged view showing a metallic supportingmember coupled to the rear plate.

FIG. 10B is a sectional view showing a flexible display unit coupled tothe rear plate.

FIG. 11A is an enlarged sectional view showing an arrangement structureof the rear plate and the flexible display unit, in a second state wherethe flexible display unit has been unfolded.

FIG. 11B is a conceptual view showing a second part in the second state.

FIG. 12A is an enlarged sectional view showing an arrangement structureof the rear plate and the flexible display unit, in a first state wherethe flexible display device has been folded.

FIG. 12B is a conceptual view showing the second part in the first statewhere the flexible display device has been folded.

FIG. 13 is a perspective view showing a rear plate according to anotherembodiment of the present disclosure.

FIG. 14A is a partially enlarged view showing a molding member coupledto the rear plate.

FIG. 14B is a sectional view showing a lamination structure of aflexible display unit coupled to the rear plate.

DETAILED DESCRIPTION OF THE INVENTION

Description will now be given in detail according to exemplaryembodiments disclosed herein, with reference to the accompanyingdrawings. For the sake of brief description with reference to thedrawings, the same or equivalent components may be provided with thesame or similar reference numbers, and description thereof will not berepeated. In general, a suffix such as “module” and “unit” may be usedto refer to elements or components. Use of such a suffix herein ismerely intended to facilitate description of the specification, and thesuffix itself is not intended to give any special meaning or function.The accompanying drawings are used to help easily understand thetechnical idea of the present disclosure and it should be understoodthat the idea of the present disclosure is not limited by theaccompanying drawings. The idea of the present disclosure should beconstrued to extend to any alterations, equivalents and substitutesbesides the accompanying drawings.

Although the terms first, second, etc. may be used herein to describevarious elements, these elements should not be limited by these terms.These terms are generally only used to distinguish one element fromanother. When an element is referred to as being “connected with”another element, the element can be connected with the another elementor intervening elements may also be present. In contrast, when anelement is referred to as being “directly connected with” anotherelement, there are no intervening elements present.

A singular representation may include a plural representation unless itrepresents a definitely different meaning from the context. Terms suchas “include” or “has” are used herein and should be understood that theyare intended to indicate an existence of several components, functionsor steps, disclosed in the specification, and it is also understood thatgreater or fewer components, functions, or steps may likewise beutilized.

Display devices presented herein may be implemented using a variety ofdifferent types of terminals. Examples of such devices include cellularphones, smart phones, user equipment, laptop computers, digitalbroadcast terminals, personal digital assistants (PDAs), portablemultimedia players (PMPs), navigators, portable computers (PCs), slatePCs, tablet PCs, ultra books, wearable devices (for example, smartwatches, smart glasses, head mounted displays (HMDs)), and the like.

By way of non-limiting example only, further description will be madewith reference to particular types of mobile terminals. However, suchteachings apply equally to other types of terminals, such as those typesnoted above. In addition, these teachings may also be applied tostationary terminals such as digital TV, desktop computers, and thelike. Hereinafter, for convenience of description, the mobile terminalwill be described as one example of a flexible display device.

FIG. 1 is a block diagram of a mobile terminal in accordance with thepresent disclosure. The mobile terminal 100 may be shown havingcomponents such as a wireless communication unit 110, an input unit 120,a sensing unit 140, an output unit 150, an interface unit 160, a memory170, a controller (or control unit) 180, and a power supply unit 190.Implementing all of the illustrated components is not a requirement.Greater or fewer components may alternatively be implemented.

In more detail, the wireless communication unit 110 may typicallyinclude one or more modules which permit communications such as wirelesscommunications between the mobile terminal 100 and a wirelesscommunication system, communications between the mobile terminal 100 andanother mobile terminal, or communications between the mobile terminal100 and an external server. Further, the wireless communication unit 110may typically include one or more modules which connect the mobileterminal 100 to one or more networks.

The wireless communication unit 110 may include one or more of abroadcast receiving module 111, a mobile communication module 112, awireless Internet module 113, a short-range communication module 114,and a location information module 115. The input unit 120 may include acamera 121 or an image input unit for obtaining images or video, amicrophone 122, which is one type of audio input device for inputting anaudio signal, and a user input unit 123 (for example, a touch key, amechanical key, and the like) for allowing a user to input information.Data (for example, audio, video, image, and the like) may be obtained bythe input unit 120 and may be analyzed and processed according to usercommands.

The sensing unit 140 may typically be implemented using one or moresensors configured to sense internal information of the mobile terminal,the surrounding environment of the mobile terminal, user information,and the like. For example, the sensing unit 140 may include at least oneof a proximity sensor 141, an illumination sensor 142, a touch sensor,an acceleration sensor, a magnetic sensor, a G-sensor, a gyroscopesensor, a motion sensor, an RGB sensor, an infrared (IR) sensor, afinger scan sensor, a ultrasonic sensor, an optical sensor (for example,camera 121), a microphone 122, a battery gauge, an environment sensor(for example, a barometer, a hygrometer, a thermometer, a radiationdetection sensor, a thermal sensor, and a gas sensor, among others), anda chemical sensor (for example, an electronic nose, a health caresensor, a biometric sensor, and the like). The mobile terminal disclosedherein may be configured to utilize information obtained from one ormore sensors of the sensing unit 140, and combinations thereof.

The output unit 150 may typically be configured to output various typesof information, such as audio, video, tactile output, and the like. Theoutput unit 150 may be shown having at least one of a display unit 151,an audio output module 152, a haptic module 153, and an optical outputmodule 154. The display unit 151 may have an inter-layered structure oran integrated structure with a touch sensor in order to implement atouch screen. The touch screen may function as the user input unit 123which provides an input interface between the mobile terminal 100 andthe user and simultaneously provide an output interface between themobile terminal 100 and a user.

The interface unit 160 serves as an interface with various types ofexternal devices that are coupled to the mobile terminal 100. Theinterface unit 160, for example, may include any of wired or wirelessports, external power supply ports, wired or wireless data ports, memorycard ports, ports for connecting a device having an identificationmodule, audio input/output (I/O) ports, video I/O ports, earphone ports,and the like. In some cases, the mobile terminal 100 may performassorted control functions associated with a connected external device,in response to the external device being connected to the interface unit160.

The memory 170 is typically implemented to store data to support variousfunctions or features of the mobile terminal 100. For instance, thememory 170 may be configured to store application programs executed inthe mobile terminal 100, data or instructions for operations of themobile terminal 100, and the like. Some of these application programsmay be downloaded from an external server via wireless communication.Other application programs may be installed within the mobile terminal100 at time of manufacturing or shipping, which is typically the casefor basic functions of the mobile terminal 100 (for example, receiving acall, placing a call, receiving a message, sending a message, and thelike). Application programs may be stored in the memory 170, installedin the mobile terminal 100, and executed by the controller 180 toperform an operation (or function) for the mobile terminal 100.

The controller 180 typically functions to control an overall operationof the mobile terminal 100, in addition to the operations associatedwith the application programs. The controller 180 can provide or processinformation or functions appropriate for a user by processing signals,data, information and the like, which are input or output by theaforementioned various components, or activating application programsstored in the memory 170.

Also, the controller 180 can control at least some of the componentsillustrated in FIG. 1, to execute an application program that have beenstored in the memory 170. In addition, the controller 180 can control atleast two of those components included in the mobile terminal 100 toactivate the application program.

The power supply unit 190 may be configured to receive external power orprovide internal power in order to supply appropriate power required foroperating elements and components included in the mobile terminal 100.The power supply unit 190 may include a battery, and the battery may beconfigured to be embedded in the terminal body, or configured to bedetachable from the terminal body.

At least part of the components may cooperatively operate to implementan operation, a control or a control method of a mobile terminalaccording to various embodiments disclosed herein. Also, the operation,the control or the control method of the mobile terminal may beimplemented on the mobile terminal by an activation of at least oneapplication program stored in the memory 170.

Hereinafter, description will be given in more detail of theaforementioned components with reference to FIG. 1, prior to describingvarious embodiments implemented through the mobile terminal 100. First,regarding the wireless communication unit 110, the broadcast receivingmodule 111 is typically configured to receive a broadcast signal and/orbroadcast associated information from an external broadcast managingentity via a broadcast channel. The broadcast channel may include asatellite channel, a terrestrial channel, or both. In some embodiments,two or more broadcast receiving modules may be utilized to facilitatesimultaneous reception of two or more broadcast channels, or to supportswitching among broadcast channels.

The broadcast management server may be a server that generates andtransmits a broadcast signal and/or broadcast associated information ora server that receives a previously generated broadcast signal and/orbroadcast associated information and transmits the same to a terminal.The broadcast signal may include a TV broadcast signal, a radiobroadcast signal, a data broadcast signal, and the like. Also, thebroadcast signal may further include a broadcast signal in a form that aTV or radio broadcast signal is combined with a data broadcast signal.

The broadcast signal may be encrypted by at least one of technicalstandards (or broadcasting methods, e.g., ISO, IEC, DVB, ATSC, etc.) fortransmitting and receiving a digital broadcast signal. The broadcastreceiving module 111 may receive the digital broadcast signal using amethod suitable for a technical standard selected from those technicalstandards.

Examples of the broadcast associated information may include informationassociated with a broadcast channel, a broadcast program, a broadcastservice provider, and the like. The broadcast associated information maybe provided via a mobile communication network. In this instance, thebroadcast associated information may be received by the mobilecommunication module 112.

The broadcast associated information may be implemented in variousformats. For instance, broadcast associated information may includeElectronic Program Guide (EPG) of Digital Multimedia Broadcasting (DMB),Electronic Service Guide (ESG) of Digital Video Broadcast-Handheld(DVB-H), and the like. The broadcast signal and/or the broadcast relatedinformation received through the broadcast receiving module 111 may bestored in the memory 160.

The mobile communication module 112 can transmit and/or receive wirelesssignals to and from one or more network entities. Typical examples of anetwork entity include a base station, an external mobile terminal, aserver, and the like. Such network entities form part of a mobilecommunication network, which is constructed according to technicalstandards or communication methods for mobile communications (forexample, Global System for Mobile Communication (GSM), Code DivisionMulti Access (CDMA), CDMA2000 (Code Division Multi Access 2000), EV-DO(Enhanced Voice-Data Optimized or Enhanced Voice-Data Only), WidebandCDMA (WCDMA), High Speed Downlink Packet access (HSDPA), HSUPA (HighSpeed Uplink Packet Access), Long Term Evolution (LTE), LTE-A (Long TermEvolution-Advanced), and the like). The wireless signal may includevarious types of data depending on a voice call signal, a video callsignal, or a text/multimedia message transmission/reception.

The wireless Internet module 113 refers to a module for wirelessInternet access. This module may be internally or externally coupled tothe mobile terminal 100. The wireless Internet module 113 may transmitand/or receive wireless signals via communication networks according towireless Internet technologies.

Examples of such wireless Internet access include Wireless LAN (WLAN),Wireless Fidelity (Wi-Fi), Wi-Fi Direct, Digital Living Network Alliance(DLNA), Wireless Broadband (WiBro), Worldwide Interoperability forMicrowave Access (WiMAX), High Speed Downlink Packet Access (HSDPA),High Speed Uplink Packet Access (HSUPA), Long Term Evolution (LTE),LTE-advanced (LTE-A) and the like. The wireless Internet module 113 maytransmit/receive data according to one or more of such wireless Internettechnologies, and other Internet technologies as well.

When the wireless Internet access is implemented according to, forexample, WiBro, HSDPA, HSUPA, GSM, CDMA, WCDMA, LTE, LTE-A and the like,as part of a mobile communication network, the wireless Internet module113 performs such wireless Internet access. As such, the Internet module113 may cooperate with, or function as, the mobile communication module112.

The short-range communication module 114 is configured to facilitateshort-range communications. Suitable technologies for implementing suchshort-range communications include BLUETOOTH™, Radio FrequencyIDentification (RFID), Infrared Data Association (IrDA), Ultra-WideBand(UWB), ZigBee, Near Field Communication (NFC), Wireless-Fidelity(Wi-Fi), Wi-Fi Direct, Wireless USB (Wireless Universal Serial Bus), andthe like. The short-range communication module 114 in general supportswireless communications between the mobile terminal 100 and a wirelesscommunication system, communications between the mobile terminal 100 andanother mobile terminal 100, or communications between the mobileterminal and a network where another mobile terminal 100 (or an externalserver) is located, via wireless area networks. One example of thewireless area networks is a wireless personal area networks.

Here, another mobile terminal (which may be configured similarly tomobile terminal 100) may be a wearable device, for example, a smartwatch, a smart glass or a head mounted display (HMD), which can exchangedata with the mobile terminal 100 (or otherwise cooperate with themobile terminal 100). The short-range communication module 114 may senseor recognize the wearable device, and permit communication between thewearable device and the mobile terminal 100. In addition, when thesensed wearable device is a device which is authenticated to communicatewith the mobile terminal 100, the controller 180, for example, may causetransmission of at least part of data processed in the mobile terminal100 to the wearable device via the short-range communication module 114.Hence, a user of the wearable device may use the data processed in themobile terminal 100 on the wearable device. For example, when a call isreceived in the mobile terminal 100, the user may answer the call usingthe wearable device. Also, when a message is received in the mobileterminal 100, the user can check the received message using the wearabledevice.

The location information module 115 is generally configured to detect,calculate, derive or otherwise identify a position (or current position)of the mobile terminal. As an example, the location information module115 includes a Global Position System (GPS) module, a Wi-Fi module, orboth. For example, when the mobile terminal uses a GPS module, aposition of the mobile terminal may be acquired using a signal sent froma GPS satellite. As another example, when the mobile terminal uses theWi-Fi module, a position of the mobile terminal can be acquired based oninformation related to a wireless access point (AP) which transmits orreceives a wireless signal to or from the Wi-Fi module. If desired, thelocation information module 115 may alternatively or additionallyfunction with any of the other modules of the wireless communicationunit 110 to obtain data related to the position of the mobile terminal.The location information module 115 is a module used for acquiring theposition (or the current position) and may not be limited to a modulefor directly calculating or acquiring the position of the mobileterminal.

Examples of such inputs include audio, image, video, data, and userinput. Image and video input is often obtained using one or more cameras121. Such cameras 121 may process image frames of still pictures orvideo obtained by image sensors in a video or image capture mode. Theprocessed image frames can be displayed on the display unit 151 orstored in memory 170. Meanwhile, the cameras 121 may be arranged in amatrix configuration to permit a plurality of images having variousangles or focal points to be input to the mobile terminal 100. Also, thecameras 121 may be located in a stereoscopic arrangement to acquire leftand right images for implementing a stereoscopic image.

The microphone 122 processes an external audio signal into electricaudio (sound) data. The processed audio data can be processed in variousmanners according to a function being executed in the mobile terminal100. If desired, the microphone 122 may include assorted noise removingalgorithms to remove unwanted noise generated in the course of receivingthe external audio signal.

The user input unit 123 is a component that permits input by a user.Such user input may enable the controller 180 to control operation ofthe mobile terminal 100. The user input unit 123 may include one or moreof a mechanical input element (for example, a mechanical key, a buttonlocated on a front and/or rear surface or a side surface of the mobileterminal 100, a dome switch, a jog wheel, a jog switch, and the like),or a touch-sensitive input element, among others. As one example, thetouch-sensitive input element may be a virtual key, a soft key or avisual key, which is displayed on a touch screen through softwareprocessing, or a touch key which is located on the mobile terminal at alocation that is other than the touch screen. Further, the virtual keyor the visual key may be displayed on the touch screen in variousshapes, for example, graphic, text, icon, video, or a combinationthereof.

The sensing unit 140 is generally configured to sense one or more ofinternal information of the mobile terminal, surrounding environmentinformation of the mobile terminal, user information, or the like, andgenerate a corresponding sensing signal. The controller 180 generallycooperates with the sending unit 140 to control operations of the mobileterminal 100 or execute data processing, a function or an operationassociated with an application program installed in the mobile terminalbased on the sensing signal. The sensing unit 140 may be implementedusing any of a variety of sensors, some of which will now be describedin more detail.

The proximity sensor 141 refers to a sensor to sense presence or absenceof an object approaching a surface, or an object located near a surface,by using an electromagnetic field, infrared rays, or the like without amechanical contact. The proximity sensor 141 may be arranged at an innerarea of the mobile terminal covered by the touch screen, or near thetouch screen.

The proximity sensor 141, for example, may include any of a transmissivetype photoelectric sensor, a direct reflective type photoelectricsensor, a mirror reflective type photoelectric sensor, a high-frequencyoscillation proximity sensor, a capacitance type proximity sensor, amagnetic type proximity sensor, an infrared rays proximity sensor, andthe like. When the touch screen is implemented as a capacitance type,the proximity sensor 141 can sense proximity of a pointer relative tothe touch screen by changes of an electromagnetic field, which isresponsive to an approach of an object with conductivity. In thisinstance, the touch screen (touch sensor) may also be categorized as aproximity sensor.

The term “proximity touch” will often be referred to herein to denotethe scenario in which a pointer is positioned to be proximate to thetouch screen without contacting the touch screen. The term “contacttouch” will often be referred to herein to denote the scenario in whicha pointer makes physical contact with the touch screen. For the positioncorresponding to the proximity touch of the pointer relative to thetouch screen, such position will correspond to a position where thepointer is perpendicular to the touch screen. The proximity sensor 141may sense proximity touch, and proximity touch patterns (for example,distance, direction, speed, time, position, moving status, and thelike). In general, controller 180 processes data corresponding toproximity touches and proximity touch patterns sensed by the proximitysensor 141, and cause output of visual information on the touch screen.In addition, the controller 180 can control the mobile terminal 100 toexecute different operations or process different data (or information)according to whether a touch with respect to a point on the touch screenis either a proximity touch or a contact touch.

A touch sensor senses a touch (or a touch input) applied to the touchscreen (or the display unit 151) using any of a variety of touchmethods. Examples of such touch methods include a resistive type, acapacitive type, an infrared type, and a magnetic field type, amongothers. As one example, the touch sensor may be configured to convertchanges of pressure applied to a specific part of the display unit 151,or convert capacitance occurring at a specific part of the display unit151, into electric input signals. The touch sensor may also beconfigured to sense not only a touched position and a touched area, butalso touch pressure and/or touch capacitance. A touch object isgenerally used to apply a touch input to the touch sensor. Examples oftypical touch objects include a finger, a touch pen, a stylus pen, apointer, or the like.

When a touch input is sensed by a touch sensor, corresponding signalsmay be transmitted to a touch controller. The touch controller mayprocess the received signals, and then transmit corresponding data tothe controller 180. Accordingly, the controller 180 can sense which areaof the display unit 151 has been touched. Here, the touch controller maybe a component separate from the controller 180, the controller 180, andcombinations thereof.

In addition, the controller 180 can execute the same or differentcontrols according to a type of touch object that touches the touchscreen or a touch key provided in addition to the touch screen. Whetherto execute the same or different control according to the object whichprovides a touch input may be decided based on a current operating stateof the mobile terminal 100 or a currently executed application program,for example.

The touch sensor and the proximity sensor may be implementedindividually, or in combination, to sense various types of touches. Suchtouches include a short (or tap) touch, a long touch, a multi-touch, adrag touch, a flick touch, a pinch-in touch, a pinch-out touch, a swipetouch, a hovering touch, and the like.

If desired, an ultrasonic sensor may be implemented to recognizelocation information relating to a touch object using ultrasonic waves.The controller 180, for example, may calculate a position of a wavegeneration source based on information sensed by an illumination sensorand a plurality of ultrasonic sensors. Since light is much faster thanultrasonic waves, the time for which the light reaches the opticalsensor is much shorter than the time for which the ultrasonic wavereaches the ultrasonic sensor. The position of the wave generationsource may be calculated using this fact. For instance, the position ofthe wave generation source may be calculated using the time differencefrom the time that the ultrasonic wave reaches the sensor based on thelight as a reference signal.

The camera 121, which has been depicted as a component of the input unit120, typically includes at least one a camera sensor (CCD, CMOS etc.), aphoto sensor (or image sensors), and a laser sensor. Implementing thecamera 121 with a laser sensor may allow detection of a touch of aphysical object with respect to a 3D stereoscopic image. The photosensor may be laminated on, or overlapped with, the display device. Thephoto sensor may be configured to scan movement of the physical objectin proximity to the touch screen. In more detail, the photo sensor mayinclude photo diodes and transistors (TRs) at rows and columns to scancontent received at the photo sensor using an electrical signal whichchanges according to the quantity of applied light. Namely, the photosensor may calculate the coordinates of the physical object according tovariation of light to thus obtain location information of the physicalobject.

The display unit 151 is generally configured to output informationprocessed in the mobile terminal 100. For example, the display unit 151may display execution screen information of an application programexecuting at the mobile terminal 100 or user interface (UI) and graphicuser interface (GUI) information in response to the execution screeninformation.

Also, the display unit 151 may be implemented as a stereoscopic displayunit for displaying stereoscopic images. A typical stereoscopic displayunit may employ a stereoscopic display scheme such as a stereoscopicscheme (a glass scheme), an auto-stereoscopic scheme (glassless scheme),a projection scheme (holographic scheme), or the like.

The audio output module 152 may receive audio data from the wirelesscommunication unit 110 or output audio data stored in the memory 170during modes such as a signal reception mode, a call mode, a recordmode, a voice recognition mode, a broadcast reception mode, and thelike. The audio output module 152 can provide audible output related toa particular function (e.g., a call signal reception sound, a messagereception sound, etc.) performed by the mobile terminal 100. The audiooutput module 152 may also be implemented as a receiver, a speaker, abuzzer, or the like.

A haptic module 153 can be configured to generate various tactileeffects that a user feels, perceives, or otherwise experiences. Atypical example of a tactile effect generated by the haptic module 153is vibration. The strength, pattern and the like of the vibrationgenerated by the haptic module 153 may be controlled by user selectionor setting by the controller 180. For example, the haptic module 153 mayoutput different vibrations in a combining manner or a sequentialmanner.

Besides vibration, the haptic module 153 can generate various othertactile effects, including an effect by stimulation such as a pinarrangement vertically moving to contact skin, a spray force or suctionforce of air through a jet orifice or a suction opening, a touch to theskin, a contact of an electrode, electrostatic force, an effect byreproducing the sense of cold and warmth using an element that canabsorb or generate heat, and the like.

The haptic module 153 can also be implemented to allow the user to feela tactile effect through a muscle sensation such as the user's fingersor arm, as well as transferring the tactile effect through directcontact. Two or more haptic modules 153 may be provided according to theparticular configuration of the mobile terminal 100.

An optical output module 154 can output a signal for indicating an eventgeneration using light of a light source. Examples of events generatedin the mobile terminal 100 may include message reception, call signalreception, a missed call, an alarm, a schedule notice, an emailreception, information reception through an application, and the like.

A signal output by the optical output module 154 may be implemented sothe mobile terminal emits monochromatic light or light with a pluralityof colors. The signal output may be terminated as the mobile terminalsenses that a user has checked the generated event, for example.

The interface unit 160 serves as an interface for external devices to beconnected with the mobile terminal 100. For example, the interface unit160 can receive data transmitted from an external device, receive powerto transfer to elements and components within the mobile terminal 100,or transmit internal data of the mobile terminal 100 to such externaldevice. The interface unit 160 may include wired or wireless headsetports, external power supply ports, wired or wireless data ports, memorycard ports, ports for connecting a device having an identificationmodule, audio input/output (I/O) ports, video I/O ports, earphone ports,or the like.

The identification module may be a chip that stores various informationfor authenticating authority of using the mobile terminal 100 and mayinclude a user identity module (UIM), a subscriber identity module(SIM), a universal subscriber identity module (USIM), and the like. Inaddition, the device having the identification module (also referred toherein as an “identifying device”) may take the form of a smart card.Accordingly, the identifying device can be connected with the terminal100 via the interface unit 160.

When the mobile terminal 100 is connected with an external cradle, theinterface unit 160 can serve as a passage to allow power from the cradleto be supplied to the mobile terminal 100 or may serve as a passage toallow various command signals input by the user from the cradle to betransferred to the mobile terminal therethrough. Various command signalsor power input from the cradle may operate as signals for recognizingthat the mobile terminal is properly mounted on the cradle.

The memory 170 can store programs to support operations of thecontroller 180 and store input/output data (for example, phonebook,messages, still images, videos, etc.). The memory 170 may store datarelated to various patterns of vibrations and audio which are output inresponse to touch inputs on the touch screen.

The memory 170 may include one or more types of storage mediumsincluding a flash memory type, a hard disk type, a solid state disk(SSD) type, a silicon disk drive (SDD) type, a multimedia card microtype, a card-type memory (e.g., SD or DX memory, etc.), a Random AccessMemory (RAM), a Static Random Access Memory (SRAM), a Read-Only Memory(ROM), an Electrically Erasable Programmable Read-Only Memory (EEPROM),a Programmable Read-Only memory (PROM), a magnetic memory, a magneticdisk, an optical disk, and the like. The mobile terminal 100 may also beoperated in relation to a network storage device that performs thestorage function of the memory 170 over a network, such as the Internet.

The controller 180 can typically control operations relating toapplication programs and the general operations of the mobile terminal100. For example, the controller 180 can set or release a lock state forrestricting a user from inputting a control command with respect toapplications when a status of the mobile terminal meets a presetcondition.

The controller 180 can also perform the controlling and processingassociated with voice calls, data communications, video calls, and thelike, or perform pattern recognition processing to recognize ahandwriting input or a picture drawing input performed on the touchscreen as characters or images, respectively. In addition, thecontroller 180 can control one or a combination of those components inorder to implement various exemplary embodiments disclosed herein.

The power supply unit 190 receives external power or provides internalpower and supply the appropriate power required for operating respectiveelements and components included in the wearable device 100 under thecontrol of the controller 180. The power supply unit 190 may include abattery, which is typically rechargeable or be detachably coupled to theterminal body for charging.

The power supply unit 190 may include a connection port. The connectionport may be configured as one example of the interface unit 160 to whichan external charger for supplying power to recharge the battery iselectrically connected.

As another example, the power supply unit 190 may be configured torecharge the battery in a wireless manner without use of the connectionport. In this example, the power supply unit 190 can receive power,transferred from an external wireless power transmitter, using at leastone of an inductive coupling method which is based on magnetic inductionor a magnetic resonance coupling method which is based onelectromagnetic resonance. Various embodiments described herein may beimplemented in a computer-readable medium, a machine-readable medium, orsimilar medium using, for example, software, hardware, or anycombination thereof.

The display unit 151 is generally configured to output informationprocessed in the mobile terminal 100. For example, the display unit 151may display execution screen information of an application programexecuting at the mobile terminal 100 or user interface (UI) and graphicuser interface (GUI) information in response to the execution screeninformation.

The display module 151 may include at least one of a liquid crystaldisplay (LCD), a thin film transistor-LCD (TFT LCD), an organiclight-emitting diode (OLED), a flexible display, a three-dimensional(3D) display and an e-ink display. The display unit 151 may beimplemented using two display devices, according to the configurationtype thereof. For instance, a plurality of the display units 151 may bearranged on one side, either spaced apart from each other, or thesedevices may be integrated, or these devices may be arranged on differentsurfaces.

The display unit 151 may include a touch sensor that senses a touch withrespect to the display unit 151 so as to receive a control command in atouch manner. Accordingly, when a touch is applied to the display unit151, the touch sensor may sense the touch, and a controller 180 maygenerate a control command corresponding to the touch. Contents input inthe touch manner may be characters, numbers, instructions in variousmodes, or a menu item that can be specified.

The microphone 122 may be configured to receive the user's voice, othersounds, and the like. The microphone 122 may be provided at a pluralityof places, and configured to receive stereo sounds.

The interface unit 160 may serve as a path allowing the mobile terminal100 to interface with external devices. For example, the interface unit160 may be at least one of a connection terminal for connecting toanother device (for example, an earphone, an external speaker, or thelike), a port for near field communication (for example, an InfraredDaAssociation (IrDA) port, a Bluetooth port, a wireless LAN port, andthe like), or a power supply terminal for supplying power to the mobileterminal 100. The interface unit 160 may be implemented in the form of asocket for accommodating an external card, such as SubscriberIdentification Module (SIM), User Identity Module (UIM), or a memorycard for information storage.

At least one antenna for wireless communication may be disposed on theterminal body. The antenna may be embedded in the terminal body orformed in the case. For example, an antenna which configures a part ofthe broadcast receiving module 111 (see FIG. 1) may be retractable intothe terminal body. Alternatively, an antenna may be formed in a form offilm to be attached onto an inner surface of the housing or a caseincluding a conductive material may serve as an antenna.

The terminal body is provided with a power supply unit 190 (see FIG. 1)for supplying power to the mobile terminal 100. The power supply unit190 may include a batter 191 which is mounted in the terminal body ordetachably coupled to an outside of the terminal body.

The battery 191 may receive power via a power cable connected to theinterface unit 160. Also, the battery 191 may be (re)chargeable in awireless manner using a wireless charger. The wireless charging may beimplemented by magnetic induction or electromagnetic resonance.

An accessory for protecting an appearance or assisting or extending thefunctions of the mobile terminal 100 may further be provided on themobile terminal 100. As one example of the accessory, a cover or pouchfor covering or accommodating at least one surface of the mobileterminal 100 may be provided. The cover or pouch may cooperate with thedisplay unit 151 to extend the function of the mobile terminal 100.Another example of the accessory may be a touch pen for assisting orextending a touch input onto a touch screen.

Next, FIG. 2A is a perspective view of a flexible display device, whichshows an outer folding state, and FIG. 2B is a perspective view of theflexible display device, which shows an unfolding state. The flexibledisplay device 200 may be understood as a type of the aforementionedmobile terminal, and the device may be referred to as a flexible displaydevice for convenience in this specification.

As shown, the flexible display device 200 includes a flexible displayunit 230 which is formed to be transformable by an external force. Inaddition, a rear plate 231 is coupled to a rear surface of the flexibledisplay unit 230. Accordingly, the flexible display unit 230 can betransformable smoothly.

Here, the transformation includes at least one of curve, bending,folding, twist and rolling of a display module. Such a transformabledisplay module can be referred to as ‘flexible display’. Here, theflexible display unit 230 may include a general flexible display,e-paper and a combination thereof.

A general flexible display indicates a display having characteristics ofthe conventional flat display, manufactured on a thin and flexiblesubstrate which can be curved, bent, folded, twisted and rolled likepaper, and thus having a light and strong characteristic. Further,electronic paper is a display technology using a general inkcharacteristic, which may be different from the conventional flatdisplay in that reflected light is used. The electronic paper can changeinformation by using twist balls, or by using an electrophoresis usingcapsules.

Further, the flexible display device 200 can have a state that theflexible display unit 230 is transformed by an external force (e.g., afolded state having a finite curvature radius, hereinafter, will bereferred to as first state, refer to FIG. 2A), and a state that theflexible display unit 230 is not transformed (e.g., a state having aninfinite curvature radius, hereinafter, will be referred to as secondstate, refer to FIG. 2B). In the second state, a display region of theflexible display unit 230 is planar.

As shown, information displayed in the first state may include visualinformation output on a curved surface. Such visual information isimplemented as light-emitting of sub pixels arranged in the form ofmatrices is controlled independently. The sub pixels mean a minimum unitto implement a single color.

The flexible display unit 230 has a curved state, not a flat state inthe first state (e.g., a curved state up and down or right and left, afolded state). In this instance, if an external force is applied to theflexible display unit 230, the flexible display unit 230 can betransformed to a flat state (or a less curved state) or a more curvedstate.

The flexible display unit 230 can include a flexible touch screen bycombining with a touch sensor. When a touch input is applied to theflexible touch screen, the controller 180 can perform a controlcorresponding to the touch input. The flexible touch screen can beconfigured to sense a touch input not only in the first state, but alsoin the second state.

In addition, the flexible display device 200 according to a modificationof the present disclosure can be provided with a transformation sensingmechanism for sensing a transformation of the flexible display unit 230.The transformation sensing mechanism may be included in the sensing unit140.

The transformation sensing mechanism be provided at the flexible displayunit 230 or bodies 210, 220, thereby sensing information related to atransformation of the flexible display unit 230. The information relatedto a transformation may be a transformation direction, a transformationdegree, a transformation position, a transformation time of the flexibledisplay unit 230, and an acceleration to restore the transformedflexible display unit 230. Also, the information may be variousinformation which can be sensed due to bending of the flexible displayunit 230.

The controller 180 can change information displayed on the flexibledisplay unit 230, or generate a control signal for controlling afunction of the flexible display device 200, based on the informationrelated to a transformation of the flexible display unit 230 sensed bythe transformation sensing means.

In addition, a state transformation of the flexible display unit 230 isnot limited to a transformation by an external force. For instance, whenthe flexible display unit 230 is in the first state, the first state canbe changed into the second state by a command of a user or anapplication.

Also, the flexible display device 200 according to an embodiment of thepresent disclosure may be provided with a case (for instance, a frame, acover, etc.) for forming appearance. The case may include the first body210 and the second body 220, and various types of electronic componentsmay be arranged in the first body 210 and the second body 220. Theflexible display device 200 may be provided on one surface of each ofthe first and second bodies 210, 220 rotatably connected to each other,and be transformed by a movement of the first and second bodies 210,220.

As shown in FIG. 2A, the flexible display unit 230 can be formed to befolded together with a movement of the second body 220 in the firststate. In more detail, the flexible display unit 230 can be folded tocover an upper surface of the first body 210 together with the secondbody 220 in an outwardly-exposed state, and a rear surface of the firstbody 210 can be overlapped with the second body 220.

More specifically, the first body 210 of the flexible display device 200supports one region of the flexible display unit 230, and the secondbody 220 of the flexible display device 200 supports another region (theremaining region) of the flexible display unit 230. Here, a plurality ofelectronic components for driving the flexible display device 200 may bemounted to at least one of the first and second bodies 210, 220. Thatis, the first and second bodies 210, 220 can perform a relative rotationin a connected state to each other, with a predetermined angle. Also,the flexible display unit 230 can be in a folded state (first state) tooverlap at least one region thereof, by being bent.

As shown in FIG. 2B, the flexible display device 200 can have anunfolding state (second state) in which the flexible display unit 230 isunfolded. In this instance, the first and second bodies 210, 220 arearranged on the same plane in parallel, and the flexible display unit230 is in an unfolded state by the first and second bodies 210, 220.Accordingly, a user can perform various tasks such as an electronic bookand a web surfing more conveniently, by utilizing a large screen.

Next, FIGS. 3A and 3B are conceptual views showing implementable statesof the flexible display device 200. As shown, the flexible displaydevice 200 can implement the first state in which rear surfaces of thefirst and second bodies 210, 220 face each other, by folding. In thisinstance, the flexible display unit 230 is arranged outside the bodiesso that an outer surface of the flexible display unit 230 is exposed tothe outside. Thus, the mobile terminal can implement a flexible displaydevice of an outer folding structure. Under the outer folding structure,the flexible display unit 230 is exposed to the outside at the time of afolding operation, and covers an outer surface of the first body 210together with the second body 220.

Further, the flexible display device 200 can have an unfolding state(second state) in which the flexible display unit 230 is unfolded. Inthis instance, the first and second bodies 210, 220 are arranged on thesame plane in parallel.

While the first state is changed into the second state, an angle formedby one region and another region of the flexible display unit 230 isvariable. Thus, the flexible display unit 230 can be gradually folded byinterworking with the angle variation. This allows the first state to beconverted into the second state.

In the first state, the first and second bodies 210, 220 are overlappedwith each other, and a space between one region and another region ofthe flexible display unit 230 is bent with a curved surface. In thisinstance, the curved surface may be implemented by a hinge unit 240.

As shown in FIG. 3A, since the second body 220 is folded to the flexibledisplay unit 230 with respect to the first body 210, the hinge unit 240is configured to enclose one side surface of the first body 210 at thetime of a folding operation. Here, one side surface of the first body210 may have a thickness greater than that of the second body 220, andthe first body 210 encloses one side surface of the second body 220together with the flexible display unit 230. As a result, an outerfolding can be implemented.

In addition, the rear plate 231 can be coupled to the rear surface ofthe flexible display unit 230. Also, the rear plate 231 can implementthe first state shown in FIG. 3A and the second state shown in FIG. 3Bby being transformed together with the flexible display unit 230.

Further, the flexible display device 200 can implement an outer foldingstructure as the rear plate 231 is transformed together with theflexible display unit 230. Under the outer folding structure, theflexible display unit 230 is in an outward-exposed state at the time ofa folding operation, and covers an outer surface of the first body 210together with the second body 220.

As shown in FIG. 3A, the flexible display device 200 can implement thefirst state in which the rear surfaces of the first and second bodies210, 220 face each other, as one side of the flexible display unit 230is folded together with the rear plate 231. Here, the outer side surfaceof the flexible display unit 230 maintains an outwardly-exposed state,and is arranged outside each of the first and second bodies 210, 220.

As shown in FIG. 3B, the flexible display device 200 can have anunfolding state (second state) in which the flexible display unit 230 isunfolded. In the second state, the first and second bodies 210, 220 arearranged on the same plane in parallel. Also, while the first state ofthe flexible display device 200 is changed into the second state, anangle formed by one region and another region of the flexible displayunit 230 is variable. This can be implemented by a transformation of therear plate 231.

In particular, the rear plate 231 can be folded by a transformation of atransformation portion 235 a (FIG. 9). Also, a region of the flexibledisplay unit 230, corresponding to the transformation portion 235 a isgradually folded as an angle of the transformation portion 235 a of therear plate 231 is changed. This allows the first state to be convertedinto the second state.

As shown in FIGS. 3A and 3B, the flexible display device 200 canimplement the first state in which the flexible display unit 230 isfolded, and the second state in which the flexible display unit 230 isunfolded. Accordingly, a user can utilize a mobile terminal which isused at ordinary times, as a note or a tablet more conveniently.

That is, the flexible display device 200 according to the presentdisclosure can implement the flexible display unit 230 having two screensizes of a folding state and an unfolding state, and can provide a userwith two modes of a phone and a note or a tablet. Further, through aninterworking structure of the bodies 210, 220, a connection operation ofa folding state and an unfolding state can be implemented in a compactspace.

Next, FIG. 4 is a planar view showing an inner form of the flexibledisplay device 200 having the flexible display unit 230 removedtherefrom, and FIG. 5 is a disassembled perspective view of the flexibledisplay device 200. As shown, the flexible display device 200 includesthe first body 210, the second body 220, the flexible display unit 230and the hinge unit 240. Under such a structure, the flexible displayunit 230 can implement a first state (folding) and a second state(unfolding).

Also, the flexible display unit 230 can implement the first state(folding) and the second state (unfolding) by movement of the first body210 and the second body 220, by being coupled to the rear plate 231.Further, the rear plate 231 can be coupled to a rear surface of theflexible display unit 230. In more detail, the rear plate 231 serves tosupport the flexible display unit 230, and can be transformed togetherwith the flexible display unit 230 as the flexible display device 200implements folding (the first state) and unfolding (the second state). Adetailed structure of the rear plate 231 will be explained later.

As shown in FIG. 5, the first body 210 can be provided with a pluralityof parts connected to each other so as to be relatively moveable withrespect to each other. For example, the first body 210 can include afirst part 212 and a second part 213. The first part 212 is a part whichcan be held by a user's hand, and forms an appearance of a rear surfaceof the first body 210.

Also, the first part 212 can be formed to have a ‘⊏’ shape. In addition,a fixing portion 215 can be formed at one side of the first part 212. Inparticular, the fixing portion 215 is formed to fix one side of links214 b to be explained later. Also, in the first part 212, the links 214b can be installed and formed to be extended and contracted according towhether or not the flexible display unit 230 is extended.

Further, the second part 213 is formed to have a ‘⊏’ E shape, and can beinstalled to face the first part 212. The hinge unit 240 can be coupledto one side of the second part 213, and the second part 213 can berotatably coupled to the second body 220. In addition, the second part213 can be installed so as to be slidable between itself and the firstpart 212. For example, both sides of the second part 213, extendedtowards the first part 212, can be slidable by being supported at bothsides of the first part 212.

Thus, the second part 213 performs a sliding operation by apredetermined distance between itself and the first part 212, therebycompensating for a length change due to folding or unfolding of theflexible display unit 230. Further, the plurality of parts of the firstbody 210 may further include a plurality of links 214 b installedbetween the first part 212 and the second part 213 and rotatablyconnected to each other, and an elastic member 216 formed to be extendedor contracted in correspondence to a movement of the plurality of links214 b.

A relative movement of the first part 212 and the second part 213 can beimplemented as the first part 212 and the second part 213 are arrangedwith the plurality of links 214 b rotatably connected to each other andthe elastic member 216 are interposed therebetween.

Further, the second body 220 has a structure to be connected to thefirst body 210 so as to be relatively rotatable through the hinge unit240, thereby implementing a folding state of the flexible display device200. Also, the flexible display unit 230 coupled to the rear plate 231is coupled to one surface of the second body 220, and a user can grasp(hold) the second body 220 for folding or unfolding.

When the flexible display unit 230 is in a folding state (the firststate), the second body 220 is arranged to cover the rear surface of thefirst body 210. In this instance, the flexible display unit 230 isexposed to the outside.

Further, the hinge unit 240 for connecting the first body 210 and thesecond body 220 to each other so as to be relatively rotatable isarranged at one side of the first body 210. As the hinge unit 240 isoperated, the second body 220 can be folded to be overlapped with thefirst body 210. Also, the flexible display unit 230 is coupled to onesurface of the second body 220, and a user can grasp (hold) the secondbody 220 for folding or unfolding.

When the flexible display unit 230 is in a folding state (the firststate), the second body 220 is arranged to cover the rear surface of thefirst body 210. In this instance, the flexible display unit 230 isexposed to the outside. Also, the hinge unit 240 for connecting thefirst body 210 and the second body 220 to each other so as to berelatively rotatable is arranged at one side of the first body 210. Asthe hinge unit 240 is operated, the second body 220 can be folded to beoverlapped with the first body 210.

The hinge unit 240 is provided with a plurality of hinge segments 241sequentially arranged in one direction (FIGS. 7A and 8A), and each ofthe hinge segments 241 is arranged to enclose the side surface of thefirst body 210 in a folding state of the flexible display unit 230.Further, the flexible display unit 230 is formed to have a flexiblecharacteristic for folding. Also, the flexible display unit 230 isarranged on the front surface of the first body 210 and the second body220, and can be transformed in correspondence to folding and unfoldingof the first body 210 and the second body 220.

As shown in FIG. 4, a main PCB 261 for processing a signal for drivingof the flexible display device 200, a battery 264 for power supply, anda driver IC for operating the flexible display unit 230 can bepositioned so as to be overlapped with the second body. Further, ahardware component 263 having various types of sensors and a cameramodule can be positioned so as to be overlapped with a first fixinghousing, and a sub PCB 262 can be positioned so as to be overlapped withthe second part 213.

Next, FIG. 6 is a perspective view showing a first state of the flexibledisplay device 200, FIGS. 7A and 7B are perspective views showing afront surface and a rear surface of hinge segments 241 of the hinge unit240, and FIGS. 8A-8C are conceptual views showing various embodiments ofthe hinge unit 240 for folding of the flexible display unit 230 of theflexible display device 200.

The hinge unit 240 connects the first and second bodies 210, 220 to eachother so as to be relatively rotatable with respect to each other, andis arranged between the first and second bodies 210, 220. Thus, thefirst and second bodies 210, 220 are connected to each other by thehinge unit 240 so as to be relatively rotatable with respect to eachother.

Since one side surface of the first body 210 has a thickness greaterthan that of the second body 220, the hinge unit 240 encloses the oneside surface of the first body 210 at the time of folding. Further, thehinge unit 240 includes a plurality of hinge segments 241 sequentiallyarranged in one direction.

Also, the hinge segments 241 are arranged to enclose one side surface ofthe first body 210 in a folding state of the flexible display unit 230.The hinge segment 241 is arranged between the first and second bodies210, 220.

As shown in FIG. 8, in the first state, the hinge segments 241 arearranged along a curved surface of the first body 210, and each hingesegment 241 is rotatably connected to its neighboring hinge segment 241for folding. The hinge segment 241 can be formed so that an interval ofat least part of its neighboring hinge segment 241 is changed by foldingand unfolding of the flexible display unit 230.

As shown in FIGS. 7A and 8B, first magnets 242 a having a magnetism maybe installed at one side of each hinge segment 241, so that the hingesegments 241 arranged to be adjacent to each other can have a rotationdisplacement. The first magnets 242 a can be installed at a plurality ofpositions of each hinge segment 241. As shown in FIG. 8B, second magnets242 b having a different magnetism from the first magnets 242 a can beinstalled at another side of each hinge segment 241.

As shown in FIGS. 8A-8C, when the flexible display device 200 is in anunfolding state in which the first body 210 and the second body 220 arearranged in parallel, the first magnets 242 a and the second magnets 242b of each hinge segment 241 are closely-attached to each other betweenthe hinge segments 241 arranged to be adjacent to each other.Accordingly, the unfolding state can be maintained.

When the flexible display device 200 has a bent shape, each of the hingesegments 241 is arranged to face the rear surface of the flexibledisplay unit 230. Here, a folding state and an unfolding state can bemaintained and a counter-bending of the hinge unit 240 can be prevented,through an elastic force of a torsion spring 244 installed at a centralregion of each of the hinge segments 241 arranged to be adjacent to eachother (FIG. 8C). That is, each of the hinge segments 241 guides foldingand unfolding of the second body 220, and a bent sectional shape thereofguides to have a predetermined curvature.

Next, FIG. 9 is a perspective view showing the rear plate 231, FIG. 10Ais a partially enlarged view showing a metallic supporting membercoupled to the rear plate 231, and FIG. 10B is a sectional view showingthe flexible display unit 230 coupled to the rear plate 231.

The rear plate 231 is coupled to the rear surface of the flexibledisplay unit 230, and can be formed to be transformable together withthe flexible display unit 230. In particular, the rear plate 231 can beformed to be folded or unfolded for the first and second states of theflexible display device 200 and may be formed of a stainless (STS) thinfilm.

Further, the rear plate 231 includes mounting portions 233 a forcoupling the rear surface of the flexible display unit 230, andtransformation portions 235 a which are transformable in correspondenceto a movement of the flexible display unit 230. Also, the rear plate 231includes a bending supporting portion 234 extended towards the outsidefrom both sides of the mounting portions.

In addition, the mounting portion 233 a for forming a bottom surface ofthe rear plate 231 can be formed in the shape of a thin plate which isextended in one direction, and can be concaved with a predetermineddepth so as to mount the rear surface of the flexible display unit 230.Further, the rear plate 231 includes a bending supporting portion 234extended towards the outside from both sides of the mounting portions233 a. The bending supporting portion 234 are bent concaved downward,and includes a bendable structure in one direction. For instance, thebending supporting portion 234 may be bent in a U-shape.

As shown in FIG. 10A, a metallic supporting member 236 can be coupled toa bottom surface of the bending supporting portion 234. In particular,the metallic supporting member 236 can be formed to have a shapecorresponding to the bottom surface of the bending supporting portion234. Also, the metallic supporting member 236 is extended in onedirection along the bottom surface of the bending supporting portion 234of the rear plate 231.

In addition, the metallic supporting member 236 can be formed tomaintain a parallel state when the flexible display unit 230 isunfolded, and to maintain a bent state when the flexible display unit230 is folded. Further, the metallic supporting member 236 can be formedof titanium (Ti) specially processed to maintain a bent state bytransformation.

The transformation portions 235 a serve to transform the flexibledisplay unit 230. The transformation portion 235 a can be formed to betransformable for implementation of folding or unfolding of the flexibledisplay unit 230. In particular, the transformation portion 235 a can betransformed so that the rear plate 231 is folded.

As shown in the enlarged part of FIG. 9, the transformation portions 235a can include a plurality of extension bars 235 c which connect bothsides of the bending supporting portion 234 arranged in parallel. Whenthe flexible display unit 230 is folded, the plurality of extension bars235 c can be bent by forming a relative movement with the neighboringextension bars 235 c, in correspondence to the movement of the flexibledisplay unit 230. Accordingly, the rear plate 231 can be folded, andthus the flexible display unit 230 coupled to the rear plate 231 can befolded.

Alternatively, the transformation portion 235 a can be formed by cuttinga selected region of the rear plate 231 by predetermined intervals. Inthis instance, the same effect can be obtained as the plurality ofextension bars 235 c which connect the bending supporting portions 234positioned at both sides of the mounting portions 233 a. Further, thetransformation portion 235 a can be formed at a position correspondingto the hinge unit 240, and can be bent for implementation of the firststate that the flexible display unit 230 is folded.

As shown in FIG. 10B, the flexible display unit 230 can be coupled tothe mounting portions 233 a by a bonding member 237. The bonding member237 may be installed between the flexible display unit 230 and themounting portions 233 a of the rear plate 231.

The bonding member 237 serves to firmly couple a lower surface of theflexible display unit 230 to a bottom surface of the rear plate 231. Inparticular, the bonding member 237 can be formed of a flexible materialso that a gap of the flexible display unit 230 is prevented, the gapoccurring when there is a space between the rear plate 231 and theflexible display unit 230, as the rear plate 231 and the flexibledisplay unit 230 are transformed.

Further, the bonding member 237 can restrict damage of the flexibledisplay unit 230 by an external force, by preventing a stress occurringbetween the rear plate 231 and the flexible display unit 230. Forinstance, the bonding member 237 may include elastomer resin having anelastic force, by using synthetic epoxy resin, etc. Accordingly, thebonding member 237 firmly couples the flexible display unit 230 and therear plate 231 to each other, and is smoothly transformed together withthe rear plate 231 in correspondence to the flexible display unit 230even if the flexible display unit 230 is transformed by folding andunfolding.

Further, the mounting portions 233 a are concaved in a U-shape. Themounting portion 233 a also include a horizontal portion 233 having aflat shape so as to be coupled to the rear surface of the flexibledisplay unit 230, and a vertical portion 232 upward extended from bothends of the horizontal portion 233 so as to cross the horizontal portion233.

In addition, the flexible display unit 230 can be coupled onto thehorizontal portion 233 of the mounting portion 233 a of the rear plate231 by the bonding member 237. Here, the flexible display unit 230 canbe formed to have the same height as the vertical portion 232. In thisinstance, since the flexible display unit 230 has the same height as thebending supporting portion 234, the appearance exposed to the outsidecan be enhanced.

Next, FIG. 11A is an enlarged sectional view showing an arrangementstructure of the rear plate 231 and the flexible display unit 230, in asecond state where the flexible display unit 230 has been unfolded, andFIG. 11B is a conceptual view showing the second part 213 in the secondstate. Also, FIG. 12A is an enlarged sectional view showing anarrangement structure of the rear plate 231 and the flexible displayunit 230, in a first state where the flexible display device 200 hasbeen folded, and FIG. 12B is a conceptual view showing the second part213 in the first state.

As aforementioned, the first and second bodies 210, 220 of the flexibledisplay device 200 are connected to each other by the hinge unit 240 soas to be relatively rotatable with respect to each other. Here, thehinge unit 240 connects the first and second bodies 210, 220 to eachother so as to be relatively rotatable with respect to each other, andare arranged between the first and second bodies 210, 220. The flexibledisplay unit 230 is also arranged on one surface of the first and secondbodies 210, 220, and can be folded and unfolded by the relativerotation.

Further, the hinge unit 240 includes a plurality of hinge segments 241sequentially arranged in one direction, and each of the hinge segments241 is arranged to enclose the side surface of the first body 210 in thefirst state that the flexible display unit 230 is folded. Here, thetransformation portions 235 a can be formed at a position correspondingto the hinge unit 240, and can be bent for implementation of the firststate that the flexible display unit 230 is folded.

Further, the transformation portion 235 a includes a plurality ofextension bars 235 c. The transformation portion 235 a can also betransformed into a shape corresponding to folding of the hinge unit 240,in order to implement the first state in which the first and secondbodies 210, 220 are overlapped with each other.

If the hinge unit 240 is folded for implementation of the first state ofthe flexible display device 200, the transformation portion 235 a of therear plate 231 are transformed in correspondence to folding of the hingeunit 240. More specifically, if the hinge unit 240 is folded, eachextension bar 235 c of the transformation portion 235 a, arranged to beoverlapped with the hinge unit 240 up and down has its position changed.

That is, if the hinge unit 240 is folded, a distance between theneighboring extension bars 235 c of the transformation portion 235 a ischanged. Accordingly, the transformation portions 235 a can be bent incorrespondence to folding of the hinge unit 240.

When the hinge segments 241 of the hinge unit 240 are converted to afolding state from an unfolding state, a distance of one end becomes farfrom a rotation center of the hinge segments 241, and the flexibledisplay unit 230 is arranged to cover the one end.

That is, as shown in FIG. 8, at the time of a folding operation, oneupper end of the flexible display unit becomes far from the rotationcenter of the hinge segments 241, whereas another lower end of theflexible display unit becomes close to the rotation center. In thisinstance, the first and second bodies 210, 220 may perform a relativesliding in order to compensate for the distance change.

That is, when the flexible display unit 230 is folded, it is required tocompensate for a length change due to a transformation of the hinge unit240. Accordingly, the elastic member 216 of the first body 210 can beextended or contracted to compensate for the length change due to atransformation of the hinge unit 240.

As shown in FIG. 12B, if the flexible display unit 230 is foldedtogether with the rear plate 231, the elastic member 216 installed atthe first body 210 is extended or contracted to thus partiallycompensate for the length change due to a transformation of the hingeunit 240. Here, a region of the rear plate 231 is fixed to the secondbody 220. Accordingly, as the elastic member 216 installed for slidingof the second part 213 of the first body 210, and the links 214 binstalled at both sides of the elastic member 216 are extended andcontracted, the length change due to a transformation of the hinge unit240 can be compensated.

Further, since the elastic member 216 is installed at the second part213, sliding of the second part 213 can be implemented. The second part213 also has a structure to be slidable towards the first part 212, andone side of the second part 213 can be connected to one of the hingesegments 241.

Further, one end of the elastic member 216 can be connected to thesecond part 213, and another end thereof can be connected to the fixingportion 215 of the first part 212. In addition, the elastic member 216provides an elastic force to the second part 213 by being compressed orextended, and to compensate for a distance due to bending of the hingeunit 240. Here, the elastic member 216 can provide an elastic force tothe second part 213 in a direction which becomes far from the hinge unit240.

As shown in FIGS. 11A and 11B, the elastic member 216 can provide amaximum elastic force in a lengthwise direction of the mobile terminal,if the hinge unit 240 and the second body 220 are spaced away from eachother to the maximum. As shown in FIGS. 12A and 12B, if the hinge unit240 and the second body 220 are close to each other to the maximum byfolding of the second body 220, the elastic member 216 is in aclosely-attached state to thus provide no elastic force.

Next, FIG. 13 is a perspective view showing a rear plate 331 accordingto another embodiment of the present disclosure, FIG. 14A is a partiallyenlarged view showing a molding member 336 coupled to the rear plate331, and FIG. 14B is a sectional view showing a lamination structure ofa flexible display unit 330 coupled to the rear plate 331.

As shown, the rear plate 331 is coupled to a rear surface of theflexible display unit 330, and can be transformed together with theflexible display unit 330. Further, the rear plate 331 can be folded orunfolded for implementation of first and second states of a flexibledisplay device 300. The rear plate 331 can also be formed of stainless(STS) thin film. In addition, the rear plate 331 includes mountingportions 333 a, 333 a′ for coupling the rear surface of the flexibledisplay unit 330, transformation portions 335 a which are transformablein correspondence to a movement of the flexible display unit 330, and abending supporting portion 334 extended towards the outside from bothsides of the mounting portions.

Further, the transformation portion 335 a of the rear plate 331 can betransformed through a position and a structure thereof, forimplementation of folding or unfolding of the flexible display unit 330.Also, a bonding member 337 is installed between the flexible displayunit 330 and the mounting portions 333 a, 333 a′ of the rear plate 331.These have been aforementioned, and thus detailed descriptions thereofwill be omitted.

However, the flexible display device 300 according to this embodimentmay also include the bending supporting portion 334 extended towards theoutside from both sides of the mounting portions 333 a, 333 a′ of therear plate 331. Here, an outer side surface of the bending supportingportion 334 may have a flat shape.

In addition, a molding member 336 can be coupled to an upper surface ofthe bending supporting portion 334. A bottom surface of the moldingmember 336 may have a flat shape to correspond to the upper surface ofthe bending supporting portion 334, and an upper surface thereof mayhave a concavo-convex shape.

When folding of the rear plate 331 is performed in an opposite directionto folding of the flexible display unit 330, interference occurs at theconcavo-convex structure formed on the upper surface of the moldingmember 336. As a result, folding of the rear plate 331 in the oppositedirection to folding of the flexible display unit 330 can be restricted.That is, the molding member 336 prevents counter-folding of the rearplate 331.

Further, the molding member 336 can maintain its parallel state when theflexible display unit 330 is unfolded, and maintain its bent state whenthe flexible display unit 330 is folded. The molding member 336 mayinclude a material such as synthetic resin.

The aforementioned flexible display device is not limited to theconfigurations and the methods of the embodiments described above, butall or some of the embodiments may be selectively combined so thatvarious modifications can be made.

What is claimed is:
 1. A flexible display device, comprising: a firstbody; a second body; a flexible display unit arranged on a front surfaceof the first body and the second body; and a hinge unit connecting thefirst body and the second body to each other such that the first bodyand the second body can be folded and unfolded with respect to eachother, wherein the hinge unit includes a plurality of hinge segmentssuch that in a folding state of the flexible display unit, the secondbody is arranged to cover a rear surface of the first body as aninterval between the hinge segments is increased, and in an unfoldedstate of the flexible display unit, the first body and the second bodyare arranged in parallel with the interval between the hinge segmentsbeing decreased.
 2. The flexible display device of claim 1, wherein inthe unfolded state of the flexible display unit, the flexible displayunit covers the hinge unit.
 3. The flexible display device of claim 1,wherein the hinge segments are sequentially arranged in one direction,and enclose a side surface of the first body in the folding state of theflexible display unit.
 4. The flexible display device of claim 1,further comprising: a rear plate coupled to a rear surface of theflexible display unit, and configured to support the flexible displayunit.
 5. The flexible display device of claim 4, further comprising: abonding member formed between an upper surface of the rear plate and abottom surface of the flexible display unit.
 6. The flexible displaydevice of claim 4, wherein the rear plate includes: mounting portionsextended in one direction, and recessed to couple the rear surface ofthe flexible display unit; transformation portions having a plurality ofextension bars arranged in parallel so as to cross the mountingportions, and being transformed in correspondence to the flexibledisplay unit; and a bending supporting portion extended towards theoutside from both sides of the mounting portions.
 7. The flexibledisplay device of claim 6, wherein the bending supporting portion isconcaved downward, and wherein a metallic supporting member is coupledto a bottom surface of the bending supporting portion, in correspondenceto a shape of the bottom surface.
 8. The flexible display device ofclaim 6, further comprising: a molding member having a concavo-convexshape coupled to an upper surface of the bending supporting portion. 9.The flexible display device of claim 6, wherein the plurality ofextension bars are arranged in parallel and spaced apart from each otherby predetermined intervals, so as to be transformed in correspondence tofolding and unfolding of the flexible display unit.
 10. The flexibledisplay device of claim 1, wherein the first body includes: a firstpart; and a second part arranged to be slidable by a predetermineddistance along the first part.
 11. The flexible display device of claim10, wherein the first body further includes: a plurality of linksinstalled between the first part and the second part, and connected toeach other so as to be relatively rotatable; and an elastic memberextended or contracted in correspondence to a movement of the pluralityof links.
 12. The flexible display device of claim 10, wherein theflexible display unit is fixedly-coupled to the first part and thesecond body.
 13. The flexible display device of claim 1, wherein thefirst body includes a plurality of parts connected to each other so asto be relatively moveable when changing between the folding andunfolding states.
 14. The flexible display device of claim 13, whereinthe plurality of parts include a first part and a second part thatslides along the first part when changing between the folding andunfolding states.
 15. The flexible display device of claim 14, whereinthe flexible display unit is fixedly-coupled to the first part.
 16. Theflexible display device of claim 1, wherein the hinge unit is exposedwhen the flexible display is in the folded state.
 17. The flexibledisplay device of claim 1, wherein the hinge segments are sequentiallyarranged in one direction, and wherein each hinge segment includes afirst magnet at a first side and a second magnet at a second side. 18.The flexible display device of claim 17, wherein in the unfolded stateof the flexible display unit, the second magnet of a first hinge segmentis adjacent to the first magnet of a second hinge segment in thesequentially arranged hinge segments.
 19. The flexible display device ofclaim 18, wherein in the folded state of the flexible display unit, thesecond magnet of the first hinge segment is spaced apart from the firstmagnet of the second hinge segment in the sequentially arranged hingesegments.
 20. The flexible display device of claim 18, wherein the firstand second magnets have opposite polarities to attract the hingesegments to be adjacent to each other.